Plague researcher dies in Siberia, Russia investigates possible outbreak

A 28-year-old laboratory worker at a plague research institute in Siberia, Russia, has died after contracting pneumonia of unknown origin, prompting quarantine measures and international concern over a possible pneumonic plague outbreak. The researcher worked at the Irkutsk Anti-Plague Institute in Shelekhov. Local authorities closed the hospital where she was treated and placed nearly 200 contacts under medical observation. Russian officials have not confirmed the cause of death, and tests reportedly found no pathogens linked to her work. The US State Department urged Moscow to provide transparent information, while experts called for greater clarity. The institute, founded in 1934, studies plague and other dangerous infections. The WHO reported no plague cases in Russia between 2019 and 2025.